ACK: [CVE-2011-4347] kvm device assignment permissions checks

Seth Forshee seth.forshee at canonical.com
Tue Feb 28 16:49:07 UTC 2012


On Tue, Feb 28, 2012 at 03:11:49PM +0000, Andy Whitcroft wrote:
> CVE-2011-4347
> 	It was found that kvm_vm_ioctl_assign_device function did not check
> 	if the user requesting assignment was privileged or not. Together
> 	with /dev/kvm being 666, unprivileged user could assign unused
> 	pci devices, or even devices that were in use and whose resources
> 	were not properly claimed by the respective drivers.  Please note
> 	that privileged access was still needed to re-program the device
> 	to for example issue DMA requests. This is typically achieved by
> 	touching files on sysfs filesystem. These files are usually not
> 	accessible to unprivileged users.  As a result, local user could
> 	use this flaw to crash the system.
> 
> Following this email are two patches.  The first is for lucid and is a
> backport from the upstream commit following the code back to an older
> filename.  The second is for maverick, natty, and oneiric and is also a
> minor backport from the upstream commit, dropping the documentation
> updates for the older releases.
> 
> Proposing for lucid, maverick, natty and oneiric.
> 
> -apw

Acked-by: Seth Forshee <seth.forshee at canonical.com>




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